1. Field of the Invention
The present invention relates to a small liquid crystal display device which is inserted in a projector for projecting an image on the liquid crystal display device onto a screen.
2. Discussion of the Related Art
The liquid crystal display device used for the purpose of the projection of an image is classified into two large groups as follows:
(I) A liquid crystal projector having a light source, a lens for magnifying the image, and a liquid crystal display panel integrally assembled in the projector; and
(II) A projector having a light source and a lens for magnifying the image, in which a liquid crystal display device is detachably mounted.
Further, the system of (II) is divided into two types.
(II-1) An over head projector (OHP) on which a liquid crystal display device is mounted. PA1 (II-2) A slide projector in which a liquid crystal display device is inserted. PA1 The systems of groups (I) and (II-1) are produced now.
Since, the system of the group (I) has the light source and the lens, manufacturing cost becomes high. Further, the system can not be used for another purpose such as a projector for projecting the slide. Since the system is large in size, it is difficult to improve portability of the system.
For the projector of the group (II-1), a liquid crystal display panel having a large size, such as size A4 must be provided. It is difficult to manufacture such a large liquid crystal display panel, because of difficulties in patterning and in providing a uniform gap between an upper glass and a lower glass of the panel, thereby deteriorating yield of the panel which causes increase of the manufacturing cost.
Japanese Utility Model Application Laid-open Publications 61-119145 and 62-12147 disclose a system of group (II-2).
FIG. 8 shows a conventional liquid crystal display device disclosed in the Japanese Utility Model Application Laid-open Publication 61-119145. The device comprises a projector 600 in which a light source 603 and a plurality of lenses 601 are provided. A liquid crystal display panel module 606 is adapted to attach to the projector 600 and electrically connected thereto through a connector 607 of the module 606 and a connector 604 of the projector 600. The module 606 is illuminated by the light source 603 and an image of the module is magnified by lenses 601 and projected on a screen 610. Since the module 606 can not be attached to an ordinary projector, the projector 600 must be carried together with modules 606.
FIGS. 9a and 9b show another conventional device disclosed in the Japanese Utility Model Application Laid-open Publication 62-12147. A holder 706 is interposed between a light source 702 and a lens 704 in a projector 700. The holder 706 is adapted to hold a slide film 707 and a liquid crystal display plate 703. The holder 706 attached to the projector 700 is reciprocated in the horizontal direction as shown by arrows a- and b in FIG. 9a, so that either of the slide 707 and the plate 703 may be selected. Thus, an image is projected on a screen 705.
In the system, since a particular projector is required, an ordinary slide projector can not be used. Consequently, the module and the holder must be carried together with the projector also in this system.